Document FR 2 865 238 discloses an electromagnetic actuator having an actuating member associated with an armature that can move under the action of an electromagnet, comprising a coil and a core suitable for channeling the flux of the coil so as to form a return path in the armature, the core having a base from which branches extend, including a central branch around which the coil extends. The electromagnet comprises two permanent magnets which are incorporated into the core in such a way that the latter channels the flux of the permanent magnets so as to form a return path in the armature, the flux of the coil passing through the magnets. In one of the embodiments illustrated in that document, the permanent magnets are placed obliquely in the lateral branches of the core, thereby making it possible to house, in the core, magnets having a length substantially equal to the height of the coil without correspondingly increasing the height of the electromagnet.
However, such an arrangement means that the laminations of the core have to be cut so as to allow the magnets to be inserted, thereby mechanically weakening the laminations and posing assembly problems. Furthermore, the gap between the core laminations and the permanent magnets depends on the precision with which the laminations are cut, something that is therefore difficult to control.